1. Field of the Invention
The present invention pertains to a process for producing a series of unit set multi-ply carbonless copy paper forms from a stack (lift) of collated sheets. More specifically, the invention relates to a pretreatment or priming of the edge of the lift to which adhesive is to be applied (padded) with water or an aqueous solution or dispersion. The pretreated edge is then dried, an edge-padding adhesive is applied, the edge is again dried and the lift is separated into individual multi-ply carbonless paper forms.
2. Description of the Prior Art
For many years carbonless copy paper has been made into form sets from a lift of collated sheets by applying an adhesive to one edge of the lift, drying the padded edge and fanning the lift into individual form sets. British Pat. No. 1,263,510 discloses an improvement in edge-padding performance by using as the adhesive a mixture of an aqueous solution of a gelatin derivative and an aqueous emulsion of a polymer. Further improvements in edge-padding are taught in U.S. Pat. Nos. 3,960,638; 3,963,553; 3,970,500; 3,970,501; and 4,041,193 where a naphthalene sulfonic acid-formaldehyde condensate is used in an edge-padding adhesive formulation in various combinations with materials such as water-soluble polymers, water-soluble binders, water-soluble metal salts, polymer emulsions, surface active agents and latexes. Japanese Pat. Publication Nos. 12844/1978 and 12845/1978 teach the use of a surface active agent with an aqueous solution of a synthetic polymer adhesive or an aqueous emulsion of a synthetic polymeric adhesive, respectively, in an edge-padding adhesive formulation. Japanese Pat. Disclosure No. 99635/1974 teaches an aqueous edge-padding adhesive composition comprising a vinyl acetatemaleic acid copolymer and various alcohols.